Commutator Length of Leaf Preserving Diffeomorphisms

We consider the group of leaf preserving C-infinity-diffeomorphisms for a C-infinity-foliation on a manifold which are isotopic to the identity through leaf preserving C-infinity-diffeomorphisms with compact support. We show that for a one-dimensional C-infinity-foliation F on the torus, this group is uniformly perfect if and only if F has no compact leaves. Moreover we consider the group of leaf preserving C-infinity-diffeomorphisms for the product foliation on S-1 x S-n which are isotopic to the identity through leaf preserving C-infinity-diffeomorphisms. Here the product foliation has leaves of the form {pt} x S-n. We show that this group is uniformly perfect for n >= 2.